Pall ring is a open-hole ring packing,which high and diameter is the same and with 5 ligules toward inside at every floor. Usually the open surface is 30% of the whole wall surface, this character helps the liguid & gas pass in packing tower pass freely from the windows of the rings.
Plastic Pall ring has good Good Capacity and Low Pressure Drop , plastic pall ring most suited in low pressure drop, high capacity applications, lpw mass-transfer unit height ,high flooding point ,uniform gas-liquid contact ,small specific gravity,high mass transfer efficiency and so on .
Metal Pall Ring has features such as thin wall, heat resistant, high free volume, high capacity, low resistance, high separation efficiency and so on. It is especially suitable for rectification towers under vacuum to treat thermo sensitive, decomposable, polymerizable or cokable systems, so it is widely used in packing towers in petrochemical industry, chemical fertilizer industry and environmental protection, etc.
Higher capacity and lower pressure drop than ceramic packing.
Multiple sizes provide ability to optimize capacity and efficiency based on application requirements.
Higher Liquid Hold-up and Residence Time
Relatively high liquid hold-up allows good absorption efficiency with slow chemical reaction.
Versatile Standard Packing
Lower sensitivity to liquid and vapor distribution quality allows use with conventional liquid distributors.
High Mechanical Strength
Ring and spoke construction provides high mechanical strength, which allows use in deep beds.
Material: polypropylene, strengthens polypropylene, hdpe, pvdf
more detail refer : http://www.chemicalpackings.com/product/plastic-pall-ring.html