Analisis Statistika Pada Pengujian Kualitas Air Boiler Water Treatment Plant (WTP) Pabrik Hot Strip Mill (HSM)

Abstract

PT XYZ is the largest steel producing company in Indonesia. In the steel making process, many raw materials are required, one of them is water (H2O). The water used in the steel-making process consists of a variety of functions, for example is a boiler water that consists of the main compound, that is Phosphate (PO4 2-), Silica (SiO2), and Hydrazine (N2H4). The presence of these compounds have a very important role in boiler water, for example as a deterrent to corrosion in boiler water pipe, so that needs to be done to control the chemical content of that compounds. Hot Strip Mill (HSM) factory is one of the plants in PT XYZ that produces steel sheet form. Water Treatment Plant (WTP) HSM is place in the factory HSM that used in the water treatment process of steel making in that factory. This study aims to look at the quality of the boiler water that used by the WTP HSM based content 3 main compound. The data used are primary data that is daily sampling from January 2011 to November 2011 with a total of 169 observations. T2 Hotelling control chart shows that there are some observations that are outside the limits. MCpm index 0.02 show that variations in process 50 times greater than the manufacturer's specifications, that meaning the process of measuring the content of chemical compounds is a lot of results that do not comply with the specifications