No description available.

Examensarbetet visar en selektivbedömning för lågspänningställverk T15 på SCA Edet bruk. Ställverket har ett 40 tal motordrifter och matas av en 690V transformator på 3,5MVA. Grundprinciper för de vanligaste lågspänningsskydden presenteras samt mer specifika detaljer om installerade skydd i aktuellt ställverk. Olika typer av selektivitet är kortfattat presenterat i rapporten. Vid beräkning och dokumentering med hjälp av datorprogrammet Febdok visade det sig att installerade skydd inte fanns med i programmets skyddsregister. Implementering har skett för merparten av skydden i anläggningen. Arbetet påvisar hur programmet Febdok arbetar samt redovisar några av de selektivplaner programmet genererat. Tyngdpunkten läggs på att kontrollera felmeddelanden som programmet genererar och relatera det till anläggningen. Ett av felen har varit att kortslutningsströmmen i ställverket överstiger brytares märkdata. Anledningen till detta är att kortslutningseffekten ökat i matande nät till transformatorn sedan byggnation. Hållfastheten för kablar har kontrollerats enligt svensk standard med avseende på stötströmmen vid en kortslutning. Kontrollen visar att några grupper inte uppfyller svensk standard.

Risk assessment of effects on the environment and health outcome caused by the iron industry Lina Löfqvist In Sweden you can find lots of contaminated areas, which can create problems for both humans and nature. To reduce the long-term contamination grades, Naturvårdsverket have created a report with regard to the contaminated sites. This builds on the ‘Method for Inventories of Contaminated Sites’ which is abbreviated MIFO. The aim of MIFO is to achieve better environmental planning in Sweden. MIFO includes two phases; phase 1 (briefs studies) and phase 2 (detailed surveys). Whit the MIFO assessment, a hazard class is obtained for the site, which is a compiled risk assessment. This is achieved by considering the hazardousness of the contamination, contamination level, conditions for contaminant dispersal, and sensitivity and protective value of the area. Strömsbergs bruk is a contaminated area outside of Tierp, which has been caused mainly by an old ironworks. Because of that, the County Board of Uppsala County, with help of the company Kemakta Konsult AB, has performed a MIFO phase 2 study at Strömsbergs bruk. The purpose with this independent project in Earth science is to analyze Kemakta Konsult’s material about Strömsbergs bruk, and then do risk assessment according to MIFO. The main contaminations found in Strömsbergs bruk are arsenic and polycyclic aromatic hydrocarbons. This has led to the area being a hazard class 2, which means high risk.

No description available.

No description available.

No description available.

De seneste årene er det oppdaget slitasjeskade på offshorevindturbinenes fortøyningsplass, hvor båter kommer inntil for på og avlastning av drift og vedlikeholdspersonell. Hensikten med denne oppgaven er å se på beleggenes egenskaper i forhold til slitasje og å få en forståelse av hvorfor slitasjeskade oppstår ved fortøyning mellom båt og vindturbin. Beleggene som er valgt ut til testing, er beleggsystemer som i dag brukes på offshorerelaterte strukturer, som oljeplattformer og vindturbiner De mekaniske egenskapene til beleggene ble undersøkt ved hjelp av vickers mikrohardhetsmåler, ruhetsmåler, slitasjeapparat og strekkapparat. • Polyester inneholder glasspartikler og fikk påvist høyest massetap, glasspartiklene kan ha falt av under slitasje og bidratt til skade på beleggoverflaten. • I slitasjetesten ble det funnet at gummi heftet på beleggenes overflate. Den avsatte gummien kan derfor ha virket som et beskyttende lag. • Det ble funnet at lang herdetid øker slitasjeegenskapene til belegget. • For epoksybeleggene og varmforsinket stål var slagfastheten bedre enn for de andre beleggene, dette skyldes god heft mellom lagene. Testene i denne oppgaven viser at det er ulike årsaker til at skade oppstår i belegg på grunn av fender. Det er funnet at glasspartikler, høy ruhet, dårlig heft mellom strøkene og kort herdetid kan ha vært årsaken til skade på belegg på grunn av fender. Et Epoksy belegg er funnet til å være det som vil være best egnet til å brukes på fender- rør.

In this master thesis experiments were conducted to determine the abrasion-corrosion properties of a steel designed for TBM tunnelling. This was done by three different tests, reciprocal ball-on-plate, rubber wheel and hyperbaric soil abrasion test. The reciprocal tests were done by rubbing steel balls onto rock obtained from a tunnel boring site in the Faroe Islands. The test were performed in dry conditions, in water from the same site as rock and a mixture of the water and a foam designed for use in hard rock tunnel boring. During these tests no measurable weight loss was produced, but the water and the foam caused some pitting to occur on the steel surface. The water and foam also provided some lubrication, where the foam clearly was the best lubricant by producing elastohydrodynamic lubrication (EHL). The rubber wheel tests were performed in different combinations of water, sand, oil and a foam specially designed for soft ground tunnel boring. The sands used were sand used for making casting moulds and sand obtained from a soft ground tunnel boring site in Israel. The two different water samples used were obtained from the site in the Faroe Islands mentioned above and the previous mentioned Israel site. The tests showed that adding foam to the sand and water mixture significantly reduced the measured weight loss. However, as for the reciprocal ball-on-plate test, the foam caused pitting to occur. The same corrosion effect was observed for the oil additive, but the oil did not provide enough lubrication to avoid abrasive wear. Consequently, the test with the oil additive produced the biggest weight loss of all the rubber wheel tests. The hyperbaric soil abrasion tests were performed in the sand obtained at the site in Israel. The sand was tested both dry and saturated with water from Israel. Tests showed that the measured weight loss from these two tests was similar. However, SEM pictures revealed that in the test with sand saturated with water, both abrasion and corrosion had occurred. While in the dry sand, only abrasion had occurred. This indicates that in this test the hardness of the steel and abrasiveness of the sand is more decisive for the weight loss than the corrosivity of the solution.

No description available.

No description available.