High efficiency separator upgrade: Threading a separator through the eye of a needle

Since 2007, the Nebraska market has been seeing increasing strength requirements. As a result, the Blaine fineness of cement produced by the 1^st generation separator finish mill systems has slowly been increasing to beyond the capability of these units. Finish mill productivity was reduced such that, where at 3,800 Blaine, the mills could easily out-grind the kilns and satisfy a highly seasonal market, the demands of producing Type I/II cement at 4,700 Blaine to meet market demands reduced the productivity such that finish mill capacity was quickly becoming a bottleneck to cement production. This paper will discuss the project to upgrade the separators at the Nebraska plant from 1^st generation to 3^rd generation in order to regain lost productivity as well as to be able to manufacture Type III cement. It will discuss the challenges of a retrofit project within an existing building along with the challenges of pre-construction while the mills are in operation, short shut-down window, as well as having a restriction of a 16' by 24' opening to fit everything through.