Filtration is critical to guarantee clarity, color and shelf life of refined edible oil. Many oil mills still use plate-and-frame filters, which come with high consumable cost, heavy manual cleaning work, high oil oxidation risk and high residual oil in filter cake.

Pressure leaf filters feature a closed pressure design, suitable for soybean oil, rapeseed oil, peanut oil, palm oil and sunflower oil refining. They are widely used for separating spent bleaching earth and activated carbon after bleaching, dewaxing in winterization, crude oil pre-filtration and final polishing filtration. The whole unit is made of food-grade 304 stainless steel.

Working Process

The filter tank is equipped with multiple stainless steel filter leaves. Before filtration, pre-coat filter leaves with filter aid (bleaching earth / diatomaceous earth) mixed with clean oil to form a uniform pre-coat layer.

Crude oil is pumped into the sealed tank. Under pressure, clean oil passes through the filter cake and screen, and flows out for next process. Fine solids, bleaching earth and wax crystals are trapped on the outside of filter leaves.

When pressure difference reaches the set value, stop feeding oil. Dry compressed air blows the filter cake to recover trapped oil and reduce oil loss. Vibration system discharges dry filter cake automatically. After simple washing, the filter is ready for the next cycle.

The fully closed operation minimizes oil contact with air and prevents oxidation.

Advantages over Traditional Filters

Reusable stainless steel filter leaves, no frequent filter cloth replacement, lower consumable and labor cost

Closed system, stable oil color and longer shelf life

Air blowing recovers oil, low residual oil in cake and higher oil yield

Automatic vibration slag discharge, low labor intensity

Compact footprint, easy to integrate into existing refining lines

Operation Notes

Control oil temperature properly according to oil viscosity. Ensure even pre-coating. Use dry compressed air to avoid oil emulsification. Regularly inspect filter screens for stable performance.