How to Choose Ceramic Foam Filter

How to Choose Ceramic Foam FilterWhen using ceramic foam filters. To determine the filter pore size depending on the number and quality of the casting liquid metal inclusions. According to the casting speed and casting weight to determine the size of the filter. To ensure the filter filtering effect. Filter placement. Gating system design should follow certain norms.

Filter installation

Filters must be placed as close to the casting. For maximum filtration efficiency and flow adjustments. From a practical factors. Such as the design of the mold can be placed in the position and gating system and the like. Filters are often placed in the runner. Sometimes the filter placed in the bottom of the sprue. But this is not recommended. Because the ceramic foam filter filtering effect and impact on liquidity will be adjusted to the bottom sprue runner turbulence. Recommended filter mounted vertically in the runner.

Select the aperture

The smaller the aperture. Filter better. But the greater the obstruction of the flow. The pore size of the filter criteria 10 ppi (10 holes per inch) (crude), 15 ppi (15 holes per inch) (middle) and 25 ppi (25 holes per inch) (fine). Steel filter pore size standard 6,10ppi. Since the iron ball after processing a large number of scum, most ductile iron factory use 10 or 15 ppi filter. Some high quality ductile iron production plant using 25 ppi filter. Because of the small pore size filter can provide better filtering effect. In these cases. We pay special attention to stable process parameters. To get a very clean ball of molten iron. Size of the filter often used fairly large. Since the dross to reduce the large number of inclusions was filtered off and cause clogged filter. Of gray iron, 15 ppi filters most widely used. For some important applications. The compressor cylinders and other pressure parts. Recommended use 25 ppi filter. This small pore size filter can effectively filter out those that cause leakage of pressure casting small-sized inclusions.

Filter thickness

Filter thickness increases. Strength of the filter, the better. Filter depth filtration efficiency is also higher. Of course, its cost is also higher. From the optimum strength and filtration efficiency considerations. Recommended use 22 mm thick filters.

Filter speed overcurrent

Most of the cast has cast a critical time. It corresponds to the optimum casting speed. Casting speed is usually derived from experience or observation of a large number of specific foundry casting instance. In certain foundry. Gating system by setting various parts of the cross-sectional area ratio (sprue cross-sectional area: a cross-sectional area of the runner and: cross-sectional area of the gate and) to ensure the proper flow rate. Various filter media are showing some degree of pressure drop. Because they greatly adjust the flow of molten iron. To reduce the impact of liquid iron filter velocity. The filter should be much larger than the flow area of the flow control area of the gating system. Filters should not be a cross-section of flow control gating system. It is recommended that the filter area of at least 2 to 5 times the flow control area.