CPT International 01/2018

CASTING TECHNOLOGY
(Photos and graphics: Foseco)
Brian Dickinson, Tony Midea, Andy Adams, Foseco Metallurgical, Inc., Cleveland, Ohio
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The analysis uses industry standard filter
print designs as the baseline for the fluid
flow comparisons, and compares these
results to filter print designs that have
been altered for yield improvement. Industry
standard filter prints are defined
as those designed during the initial filter
development for iron castings. Some
of the key requirements for optimal results
were identified during the development,
incl. the following [1-4],[6-11].
» Maximize exposure of the filter inlet
face to ensure maximum total flow
» Maximize (four sided) support to ensure
that the inertial forces on the filter
from the iron flow do not surpass
the strength of the filter
» Minimize the possibility of iron
passing around (not through) the
filter by designing the support ledge
on the filter print outlet to match filter
tolerance dimensions
» Minimize turbulence by designing
the filter print volumes such that
the flow smoothly transitions from
inlet to outlet
These combined characteristics were
used to define the basis for standard filter
print design. Over the past 30 years,
these designs have been continually tested
and have slightly evolved through applications
and foundry evaluations. The
first simulations conducted in this study
were used to evaluate these standard designs.
Yield improvement is a high priority
for all foundries, and gating systems
are analyzed as carefully as all other
aspects of the casting process to reduce
weight. Alterations are sometimes
made to standard filter prints to reduce
weight without careful analysis of the
effect on the fluid flow properties on
the gating system.
20 Casting Plant & Technology 1 / 2018