How to Choose Ceramic Foam Filter?
Updated: Aug 9, 2021
Factors to consider: casting material, pouring temperature, pouring head height, pouring volume, pouring time, the placement of filter in the pouring system...
Confirm the pore size of filter according to the quality of casting and the number of inclusions in the molten metal;
Confirm the filter size according to the pouring speed and pouring weight;
Pore size(PPI=Pore Per Inch)
commonly used pore size: 10PPI, 15PPI, 20PPI, 25PPI, 30PPI
The smaller the pore size, the better the filtering effect; but the greater the obstacle to flow.
For cast steel, the filter PPI is usually 6PPI, 15PPI;
For ductile iron which has a lot of scum, most foundries use 10PPI, 15PPI, some high quality foundries use 25PPI;
For gray iron, usually use 15PPI;
The thickness of filter
The greater the thickness, the better the strength, the higher efficiency of deep filtration.
The commonly used thickness is 22mm;
Large casting such as non-ferrous alloys: 20~25mm;
Cast iron: 22mm
Steel casting: ≥25mm;
At high temperatures, the time that the filter can withstand molten metal scouring is limited. So the amount of molten metal filtered per unit area of the filter is limited.
The maximum filtering capacity per square centimeter is :
cast iron: < 1kg (0.5~1kg/cm2)
ductile iron: < 2kg (1~2kg/cm2)
gra iron: <4kg (2~4kg/cm2)