Patent ID: 7666248
Filing Date: 2010-02-23
Classification: B22D

Abstract:
1. A method of priming an in-line molten metal filtration unit having a porous ceramic or refractory filter mounted substantially horizontally in a filter box having an inlet for molten metal and an outlet for molten metal, the outlet being a closeable outlet in an exit well connecting to the downstream side of the filter, the method comprising the steps of adding sufficient molten metal to the filter box to fully cover the upstream side of the filter with a depth of molten metal, temporarily closing the molten metal outlet in the exit well with a sealable cover, applying a steadily increasing vacuum to the closed chamber at a rate between 0.1 and 10 kPa per second by withdrawing a stream of air from the exit well through a fan or air venturi until the molten metal begins to flow through the filter and then immediately releasing the vacuum and removing the sealable cover from the molten metal outlet.