A multi-zone
filtration device for a down-flow catalytic hydroprocessing reactor is disclosed. The
filtration device may be used in the
petroleum and chemical
processing industries in catalytic reactions of hydrocarbonaceous feedstocks in the presence of
hydrogen, at an elevated
temperature and pressure, to remove contaminants from
mixed gas and liquid feedstreams to reactor catalyst beds. The
filtration device may be provided as a horizontal installation at the top of a reactor, whereby feedstream liquid is passed through filtration media zones in a radial flow direction. In one zone, the flow is radially outward from the center of a zone of the filtration device to the wall of the reactor. In another zone, the flow is radially inward from the wall of the reactor to the center of a zone of the filtration device. The liquid flows to the reactor catalyst
bed after passing through the filtration device. Among the benefits provided are the minimization of scale and small / fine
particulates that reach the catalyst
bed below the device, reduced pressure drop through the reactor, even when the filter is completely fouled, the potential for added catalyst volume due to the reduced need to use catalyst grading materials, and the improved potential for reduced maintenance needs during reactor operation, e.g., top
bed skimming or filtration media replacement, thereby extending the reactor run time length.