The use of adsorption on the surface of the adsorption (activated carbon) filter, there is the use of a limited period, the adsorbent oil adsorption capacity will also reduce its problems. Absorbent filters, such as wool, linoleum, and cotton, are the main materials used for absorbent filters, losing their structural advantage and rapidly losing their ability to absorb liquids and impregnate them. Mechanical separators and screen air filters , Usually classified by 5, 10, 20 and 40 μm, is ineffective for the tiny particles that make up most of the oil droplets.