Drum oil skimmers use the principle of selective adhesion to separate oil from water.

Principles of density difference and adhesion to separate oil from water. A rotating drum, made of a material that attracts oil (oleophilic), is partially submerged in the water, attracting floating oil to its surface. Scrapers or wiper blades then remove the collected oil from the drum, depositing it into a collection trough. 

TDS118 Oil Skimmer

Here's a more detailed breakdown:

1. Adhesion and Oleophilicity: The drum's surface is designed to be oleophilic, meaning it has a strong affinity for oil compared to water. This allows the drum to readily pick up floating oil from the water's surface. 

2. Density Difference: Oil is generally less dense than water, causing it to float on top. This density difference contributes to the oil's tendency to adhere to the drum's surface as it rotates. 

3. Scraper Mechanism: As the drum rotates, a scraper or wiper blade is positioned to remove the collected oil from the drum's surface. This scraped oil is then directed into a collection trough for storage or further processing. 

TDS118 Oil Skimmer

4. Efficiency and Applications: Drum skimmers are known for their high oil recovery rates and their ability to operate in shallow water conditions. They are widely used in various applications, including oil spill response, waste-water treatment, and industrial processes. 

Drum oil skimmers use the principle of selective adhesion to separate oil from water. The drum, often made of an oleophilic material, is designed to attract and adhere to oil more readily than water. As the drum rotates, the adhered oil is scraped off and collected, effectively skimming the oil from the water surface. 

Elaboration:

Oleophilic Material:

The drum is made from a material that has a strong affinity for oil (hydrocarbons), meaning it will attract and stick to oil more easily than water. Common materials include stainless steel, rubber, or polyurethane. 

Selective Adhesion:

The drum's surface is designed to maximize the area for oil to adhere. Grooves or ridges on the surface can increase the contact area and promote better oil adhesion. 

Rotation and Scraping:

As the drum rotates, it picks up the floating oil from the water surface. Wiper blades or scrapers remove the oil from the drum, directing it into a collection trough. 

Separation:

The collected oil is then pumped to a storage location, leaving the water relatively clean. 

Advantages:

Drum skimmers are versatile and can operate in shallow drafts, making them suitable for various applications, including oil spill cleanup and oily wastewater treatment. They are also relatively simple and effective, and can often achieve the desired level of water purity on their own,