In the last article, we have discussed why the oil industry need the filtration process. There are two types of the depth filtration ,the direct flow filtration filter and the axial flow filter. In the later passage, we are gonna introduce the axial flow depth filter.
The axial flow depth filter uses the special media, which is the generally high strength cellulose paper that has been creped before rolling. Unlike other filter cartridges, the liquid raw material may pass through the filter media, the axial flow depth filter allow the liquid raw material flow along the layers of the roll of the media. If the oil only require the low ISO Cleanliness level, this type of media would be appropriate. It can remove the impurities effectively and the price is relatively inexpensive.
The Axial Flow Depth Filter has more filtration media than the other filter cartridge thus it ca hold more solid contamination and water. The filter media usually has 8 pounds of paper media, which can hold 10 pounds solid contamination and 1 gallon water.
While the elements are being constructed and the paper is being rolled, it is stretched slightly to allow the creping to open wider than its normal amount. As the paper gets rolled layer upon layer, the creping goes back to its relaxed state creating an interlocking of the layers in the roll.
This is important because as the oil flows between the layers of paper, the interlocked creping form a jagged flow path to help dislodge the contamination from the oil.