Rus Aluminium requires that the selection of ceramic foam filters should be based on the quality requirements of the casting and the number of inclusions in the molten metal to determine the pore size of the filter. The size of the filter is determined according to the pouring speed and pouring weight.
Rus Aluminium said that when choosing a ceramic foam filter, the following aspects must be considered.
Pouring material / pouring temperature / pouring head height / pouring amount / pouring time
In order to ensure the filtering effect of the filter, the placement of the filter and the design of the pouring system should also follow certain specifications.
The installation of the filter The filter must be as close as possible to the casting to obtain the maximum filtration efficiency and flow adjustment.
Taking into account practical factors, such as the position that can be placed in the mold and the design of the gating system, the filter is usually placed in the runner.
Sometimes the filter is placed at the bottom of the main runner, but this is not recommended.
Because the filtering effect and flow adjustment of the ceramic foam filter will be affected by the turbulence from the bottom of the main runner to the runner. Rus Aluminium recommends installing the filter vertically in the flow channel.
Flow rate of ceramic foam filter
Most castings with filtered flow rates have a critical pouring time corresponding to the optimal pouring speed.
The pouring speed usually comes from the experience or observation of a large number of castings in a certain foundry.
In some foundries, by setting the cross-sectional area ratio of each part of the gating system (the cross-sectional area of the gate: the sum of the cross-sectional area of the gate: the sum of the cross-sectional area of the inner gate) to ensure proper flow.
Various filter media exhibit a certain degree of pressure drop due to the adjustment effect on the flow of molten iron.
In order to reduce the influence of the filter on the speed of molten iron, the flow area of the filter should be much larger than the flow control area of the pouring system.
Metal overflow before the filter is clogged All filters have a limit metal overflow before they are completely clogged.
Since the inclusions are filtered out, the effective flow area of the filter is reduced, and flow blockage occurs.
In extreme cases, exceeding this limit will cause the flow through the filter to stop completely.
The flow rate of the filter varies greatly with the content of inclusions in the molten iron, pouring temperature and pouring system design.
The foundry can determine how much flow area the filter needs based on the flow value of the casting and the pouring weight.